A. Field of the Invention
This invention lies in the area of oil content analyzing apparatus and methods, and, more particularly, in the area of means and methods for detecting trace amounts of oil in the water being tested.
B. Description of the Prior Art
The need to detect small, or trace amounts of oil in water is a need which has long been present in a variety of commercial and other areas. However, the relatively recent emphasis on protecting and maintaining the marine environment has underscored the need for development of accurate and reliable instrumentation for the detection and measurement of trace amounts of oil in water. The instrumentation presently available, which utilizes present state of the art techniques and devices, is simply not adequate for widespread reliable and commercially feasible utilization. The present instrumentation lies generally in two categories. The first category of device employs the Noll method which uses a gravimetric procedure, i.e., weighing of a sample, and requires that the water sample be taken to a laboratory to determine the oil, or hydrocarbon content of the sample being analyzed. The second type uses the sophisticated technique of spectrophotometry, whereby the presence of hydrocarbons is detected by their absorption of energies in their characteristic ultraviolet and infrared areas of the spectrum. It is understood that attempts have been made to package these devices for on-site analysis, e.g., on boats, but this results in large and expensive instrument packages. Detection of oil in water by these methods and systems requires expensive instrumentation costing literally thousands of dollars, which necessarily limits their use to a relatively small segment of the industrial market. The net effect of the inadequacy of the presently available devices is that many users simply don't have the instrumentation that they desire and, in many cases, need in order to comply with legal regulations. As an example, recreational boat owners, who number in the millions, are required to limit the oil content of discharged bilge water to a limit as low as 15 parts per million of oil. Clearly, for this portion of the large segment of prospective users of oil detection equipment, there is a very great need for a relatively inexpensive and reliable oil detection device having the required sensitivity.